Practice Test


1) The radioactive decay follows


2) The group displacement law was proposed by


3) The nuclei which are not identical but have same number of nucleons represent


4) The positron is nearly as heavy as


5) The triad of nuclei that is isotonic is:


6) Which of the following is an artificial man-made series?


7) The age of minerals and rocks is estimated by


8) Which sub-atomic particle is more effective in bringing about artificial transmutation of elements?


9) On passing through a magnetic field, the greatest deflection is experienced by


10) In nucelar reactors, the moderator is:


11) Bismuth is the end product of the radioactive disintegration series known as:


12) Which of the following is an example of induced radioactivity?


13) Which of the following is considered as a synthetic element?


14) The energy released in nuclear reactions corresponding to 1 a.m.u. is about


15) Uranium series is also known as


16) Radioisotopes have been used in treatment of certain diseases. For treatment of cancerous tumors, the raidoisotope used was


17) The radiant energy of the sun is due to


18) The phenomenon of nuclear fission was experimentally observed by


19) Which is used as a neutron absorber in nuclear reactors to control the chain reaction?


20) Average life period is equal to


21) If an element emits an alpha- particle, then the position of daughter element will be displaced in the periodic table by


22) The equipment used to carry out the fission reaction in a controlled manner is called


23) The radioactive isotope of carbon used in radio carbon dating is


24) The first positron emitter discovered was:


25) Which of the following process results in emission of X-rays?


26) The basic principle in the hydrogen bomb is:


27) If in the reaction of fluorine-19 with a neutron nitrogen-16 is formed, what is the other particel given off in the reaction?


28) Which of the following represents fusion reaction?


29) When the quantity of a radioactive substance is increased to two times, the number of atoms disintegrated per unit time is:


30) A positron has a charge equal to that of


31) The decive used for the measurement of radioactivity is:


32) Which of the following is not a transuranic element?


33) In a breeder reactor, which of the following is converted to fissionable fuel?


34) Which of the following is a thermonuclear reaction?


35) The mass of 1 curie of U-234 is:


36) If a radioactive element is placed in an evacuated container, its rate of disintegration will


37) The half period of a radioactive element is 20 years. If a sample of this nucleide has an initial activity of 20000 dis/min, the activity after 80 years would be


38) The substance used in Breeder reactor is:


39) Which of the following nuclei is unstable?


40) The activity of radioactive isotope decreases with


41) The artificial radioactivity was first discovered by


42) With time, the rate of radioactivity disintegration


43) Which of the following transformation is not correct?


44) Which of the following used in dating archaeological findings?


45) Which of the following radiations can be easily stopped by air?


46) Meson was discovered by


47) Neutrino can be detected during the emission of


48) Packing fraction is related to


49) Lead containers are generally used for storing radioactive materials. This is because


50) Nuclear energy is the result of conversion of


51) The half-life period of a radioactive substance is 140 days. After 560 days, one gram of the element will be reduced to


52) During the fission of U-235, a large amount of energy of the order of 180 MeV is generated per nucleus fissioned. The amount of energy released by the fission of 0.235 g of U-235 is:


53) The half life period of a particular isotope is 10 years. Its decay constant is:


54) The half life period of a radioactive isotope of X is 15 hours. How long will it take for its activity to be reduced to 1/16 of its original value?


55) A certain radioactive substance has half life period of 10 days. How long will it take for its activity to reduce to 1/8 of its original value?


56) Eight grams of a radioactive susbtance is reduced to 0.5 g after 1 hour. The half life period of the radioactive substance is:


57) A radioactive substance having a half life period of 5 days was recevied after 20 days. It was found that there was 3 g of the isotope in the container. The initial weight of the isotope when placed was:


58) Carbon-14 has a half life period of 5760 years. 100 mg of sample containing C - 14 is reduced to 25 mg in


59) Starting with 10 g of a radioactive substance 0.1 g is left after 10 days. The rate constant for the decay is:


60) The half life period of a radioactive nucleide is 1 hour. In three hours its activity will be reduced by a factor of


61) The half life period of a radioactive element is 120 days. Starting with 1 g, the amount of element decayed in 600 days will be


62) The most stable nuclei have mass number


63) Which of the following statements is not correct?


64) A raditoactive sample has a half life of 1500 years. A sealed tube containing 1 g of the sample will contain after 3000 years


65) The half life period of a radioactive substance is 15 miuntes. What per cent of radioactivity of that material will remain after 45 minutes?


66) A radioactive isotope decays at such a rate that after 96 minutes only 1/8 th of the original substance is left. The half life period of the nucleide is:


67) In a radioactive decay, an emitted electrons comes from


68) 8 g of the radioactive isotope, cesium- 137 were collected on Feb, 1 and kept in a sealed tube. On July 1, it was found that only 0.25 g of it remained. So the half life period of the isotope is:


69) The isotopes of elements were discovered by


70) Which of the following is used in cancer therapy?


71) A radioactive substance having a half life period of 3 days was received after 12 days. It was found that there was 3 g of the isotope in the container. The initial weight of the isotope when placed was:


72) A radioactive element has a half life of one day. After three days, the amount of element left will be


73) Carbon- 14 dating method is that the


74) The half-life of a radioactive nucleide 'X' is 24 hours, the time required for 12.5% of the original X to remain is


75) A radioactive substance has half life 5760 years. 100 mg of a sample containing the substance is reduced to 25 mg in


76) If amount of radioactive substance is increased three times, the number of disintegrating atoms per unit time will


77) A radioactive element (atomic mass = 90 a.m.u.) has half life of 28 years. The number of disintegration per second is


78) The introduction of a neutron into the nuclear composition of an atom would lead to a change in


79) The half life of radioisotope is 4 hr. If the initial mass of the isotope was 200 g, the mass remaining after 24 hr. undecayed is


80) Which of the following nuclear reaction will generate an isotope?


81) A radioactive element gets spilled over the floor of a room. Its half-life period is 30 days. If the initial activity is ten times the permissible value, after how many days will it be safe to enter the room?


82) The half life of a radioactive isotope is three hours. If the initial mass of the isotope was 300 g, the mass which remained undecayed in 18 hours would be


83) The half life period of a radio active substance is 5 years. The value of decay constant is:


84) Isobar of a nucleide is formed when _________ takes place?


85) Neutron was discovered by


86) A human body required 0.01 M activity of a radioactive substance after 24 hours. Half life of the radioactive substance is 6 hours. The injection of maximum activity of the radioactive substance that can be injected is


87) Which of the following used as moderator in a nuclear reactor?


88) Half life of a radioactive substance which disintegrates by 75% in 60 minutes will be


89) The phenomenon of a radioactivity arises from the


90) Which of the following is easily stopped by air?


91) The reactor used to convert stable form to fissile form is


92) Unstable substances exhibit higher radioactivity due to


93) Which one of the following radio isotopes is used in the treatment of blood cancer?


94) Most radioactive is


95) Which of the following isotope of uranium is most radioactive?


96) The order of density of nucleus is


97) The element used for dating the ancient remain is


98) Fusion bomb involves


99) If radium and chlorine combine to form radium chloride the compound is


100) The half lives of two radioactive nucleides A and B are 1 and 2 min. respectively. Equal weights of A and B are taken separately and allowed to disintegrate for 4 min. What will be the ratio of weights of A and B disintegrated?


101) If a substance with half life of 3 days is taken to another place in 12 days. What is the amount of substance left now?


102) Which of the following is a spallation reaction?


103) A positron is represented as:


104) Which of the following is man made series?


105) The activity of a sample has 40% as much radioactivity as present originally. If the half life period of the radioactivity is 3000 y, the life of the sample undergoing disintegration is


106) One Becquerel of radioactivity is equal to


107) A radioactive nucleide emits particles alpha, beta and gamma in successive disintegration. The atomic mass of the end product is less than the atomic mass of the original uncleide by approximately


108) The half life period of a radioactive substance is 15 days. How long will take for 3/4 of the atoms originally present to disintegrate?


109) The radioactive isotope used to estimate the age of ancient geological formation is


110) The half life period of a radioactive element is 72 days. After 288 days one gram of the element will reduce to


111) In a nuclear reactor, the moderate is


112) If 10.0 g of a radioactive substance has a half life of 32 hr, the half life of 2.5 g of the same substance is


113) Decrease in atomic number is not observed during


114) The radioactive disintegration equation may be expressed as:


115) Alpha particles are